If you’ve been battling stubborn acne, you may want to look farther than your skincare routine. The secret to clearer skin could be hiding in your gut. Thanks to the gut-skin axis, research suggests that an imbalanced gut microbiome can contribute to inflammation, breakouts, and even conditions like eczema. Probiotics are a novel approach to treating acne from the inside out. But with so many probiotic supplements on the market, how do you know which ones actually work for acne? In this guide, we’ll break down the best probiotics for acne, explain how they support both your gut and skin, and help you find the right one for your needs. We will also discuss what particular dietary changes could improve your acne.
What is Acne?
Acne is a chronic inflammatory skin disease characterized by whiteheads, blackheads, pustules, papules, cysts, and other eruptions. It is highly prevalent, affecting 95% of boys and 83% of girls by age 16, and affecting 85% of 11-30 year olds (1) (2). Several factors contribute to the development of acne, including genetics, hormones, increased sebum (oil) production, and the skin bacteria Cutibacterium acnes (C. acnes) (1).
Why is Treating Acne Important?
In addition to physical effects such as permanent scarring, acne is associated with severe psychological effects. Even mild acne often significantly reduces quality of life and is linked to depression, anxiety, social isolation and loneliness, suicidal ideation, and lower self attitude, pride, body satisfaction, and self worth. It further leads to negative life outcomes such as higher unemployment rates in adults and lower social status. Fortunately, research suggests treating acne also remedies these associated psychological effects (2). Therefore, furthering our understanding of acne to facilitate effective treatment should be of utmost priority!
What Causes Acne?
Skin Bacteria
C. acnes is considered the most causal bacteria of acne, despite also being present in healthy skin. In fact, C. acnes is vital for balancing skin pH and preventing the growth of pathogenic (bad) bacteria like S. aureus and Streptococcus. However, certain ‘unhealthy’ subgroups of C. acnes are associated with the production of reactive oxygen species which cause inflammation in skin cells including keratinocytes (the main type of cell in the outer layer of our skin) and sebocytes (sebum/oil producing cells), leading to acne (1) (3).
Androgen Hormones
However, the presence of unhealthy C. acnes strains does not correlate with acne severity, suggesting other factors are also responsible for the inflammation underlying acne (3). Androgen hormones (male sex hormones like testosterone) are believed to be one of the primary culprits, evidenced by the fact that both male and female acne patients often exhibit increased levels of androgens and that acne typically begins in adolescence when androgen production increases. Androgens interact with androgen receptors in sebocytes and keratinocytes which increases sebum production and inflammation (1).
The Gut-Skin-Axis
More recently, researchers have discovered the existence of the “gut-skin axis”. This refers to the significant impact the gut microbiome and skin health have on each other. Unsurprisingly, acne patients have elevated risk for gut issues like constipation, reflux, bloating, and small intestinal bacterial overgrowth (SIBO). In fact, 40% of acne patients complain of constipation. Treating gut issues such as SIBO has also been shown to improve acne, further supporting this as a causal relationship (4).
The exact mechanisms underlying this relationship remain unknown, however it is believed to primarily be via the inflammatory immune system, whereby the gut microbiota impacts the composition and functionality of the immune system and vice versa. Although skin microbes like C. acnes also interact with the immune system, the communication with gut microbes is likely more significant, as the intestines contain 70% of the body’s immune cells and is more densely populated with microbes than the skin (3).
Accordingly, gut dysbiosis (microorganism imbalance) is very common in acne patients. Volkova et al (2001) found 54% of acne patients presented with gut dysbiosis. Other studies have shown acne patients have lower levels of Bifidobacterium and Clostridia but higher levels of Proteobacterium. Bifidobacteria are beneficial because they inhibit the growth of pathogenic (“bad”) bacteria and decrease intestinal permeability. Meanwhile, Clostridial family bacteria produce beneficial short chain fatty acids (SCFAs) (3). Since SCFAs are toxic to C. acnes, underproducing them decreases the skin’s resistance against it, hence promoting acne (1). On the other hand, Proteobacteria can be harmful because they increase lipopolysaccharide (LPS) endotoxin and intestinal permeability.
Increased intestinal permeability appears characteristic of acne. Endotoxins such as LPS endotoxins produced from gut microbes are more common in acne patients than healthy individuals. This suggests that acne patients have weaker intestinal barriers (increased intestinal permeability) which allows these toxic substances to exit the intestines and enter the blood where they trigger inflammation and insulin resistance. Interestingly, 40% of acne patients have hypochlorhydria (low stomach acid) which could enable bacteria to migrate from the large intestine to the small intestine, leading to increased intestinal permeability, dysbiosis, SIBO, and inflammation (4).
Can Probiotics Treat Acne?
Our recently increased understanding of the importance of a healthy gut for preventing acne has sparked interest in treating the gut in order to alleviate acne. In particular, probiotics have been proposed as a treatment. Probiotics are living microorganisms shown to benefit human health when given in sufficient quantities via drugs, cosmetics, supplements, foods, or food additives. Probiotics could resolve acne through various mechanisms. They may bind to the skin where they can prevent pathogen growth, produce antimicrobial compounds that inhibit C. acnes, reduce inflammation, and support the immune system (1). For example, probiotics have been shown to inhibit the inflammatory cytokine IL-8 in epithelial cells and keratinocytes, indicating their likely role in the inflammatory immune response (5). They may also reduce release of substance P which contributes to sebum production (4).
As our knowledge of the gut microbiome remains primitive, human trials of probiotics for treating acne are still emerging. Nonetheless, trials have produced promising results, particularly when considered in conjunction with in vitro studies (3). However, not all probiotics are equally effective. The best probiotics for acne are Bifidobacterium and Lactobacillus (1). These bacteria have also been linked to gastrointestinal health separately from acne, with a 2005 study noting patients with constipation had lower levels of both, as well as increased intestinal permeability (4). This evidence further strengthens the importance of the gut-skin axis.
Bifidobacteria as an Oral Probiotic
Bifidobacteria can improve glycemic control which is associated with decreased acne risk. This is because Bifidobacteria can strengthen the intestinal lining, and thus prevent LPS endotoxins from permeating into the blood. Bifidobacteria probiotics may both decrease the levels of these LPS endotoxins in the blood as well as the body’s reactivity to these toxins (4). Studies administering Bifidobacteria probiotics have noted reduced inflammatory markers and reduced growth of C. acnes (3).
Lactobacillus as an Oral Probiotic
Lactobacillus probiotics were first used for acne all the way back in a 1961 study where 80% of the 300 acne patients given Lactobacillus acidophilus and Lactobacillus bulgaricus tablets for just 16 days experienced clinical improvements (4). Other studies have found Lactobacillus probiotic tablets and Lactobacillus-fermented dairy reduce sebum production, lesion count, and inflammatory markers (4). Overall, Lactobacillus has been shown to reduce inflammation and prevent intestinal permeability (3) (4).
Other Probiotics for Acne
There is a growing list of probiotics that are being investigated for benefit in treating acne. Here is a list of how some of these probiotics may benefit acne:
- Staphylococcus epidermidis: ferments glycerol which can prevent C. acnes growth (5)
- Streptococcus salivarius: produces bacteriocins that inhibit C. acnes growth. Also stimulates an anti-inflammatory response by adhering to the epithelial surface to protect against pathogen-induced inflammation (3)
- Saccharomyces cerevisiae: reduces intestinal permeability and constipation (4)
- Weissella viridescences: positively impacts the inflammatory response. It additionally inhibits C. acnes growth by reducing its adhesion to skin cells (1) (3)
Topical Probiotics as a Treatment for Acne
In addition to oral supplements, probiotics can be added to cosmetic and skin care products for topical use. Topical probiotics can improve skin moisture and trigger lipid production and repair processes in the epidermis. Additionally, they serve as a physical barrier, protecting against pathogens while promoting the growth of beneficial bacteria. As a result, they reduce toxic metabolites, and inflammatory cytokines yet increase antibody production and restore homeostasis of the immune system and skin pH (1).
Some topical probiotics demonstrated in research to be effective include:
- Streptococcus salivarius: promotes production of enzymes that moisture the skin (1)
- Streptococcus thermophilus: increases production of ceramides which help the skin retain moisture and acts as an antimicrobial against C. acnes (1)
- Enterococcus faecalis: when used in lotion has been shown to reduce papules and pustules in mild to moderate acne (1). This lotion is also shown to decrease inflammatory lesions (3).
- Lactiplantibacillus plantarum: cream containing this probiotic reduced C. acnes growth and improved skin moisture and acne spots (1)
The Role of Diet in Acne Management
While probiotics and other topical and oral treatments can combat acne, it is also important to highlight the significance of diet.
It is hypothesized that consuming a high glycemic index (GI) diet promotes acne. High GI foods are those that significantly spike blood sugar such as simple sugars. Foods rich in protein, fat, and fibre meanwhile blunt this blood sugar rise and are considered low GI. This is because meals with a high glycemic load lead to a rise in insulin and insulin-like growth factor 1 (IGF-1) in the body which alter gene expression to trigger inflammation, androgen production, and proliferation of keratinocytes, hence causing acne (1) (3). A high GI diet can also increase the expression of mTOR, a nutrient sensitive regulator that impacts skin cell growth. Errors in the mTOR pathway can affect the gut microbiome as well as increase intestinal permeability. Agamia et al. (2016) found acne patients had both higher IGF-1 concentrations and more intense expression of mTOR, suggesting a high GI diet may be at play (3).
Similarly, some dairy products have been linked to acne, possibly also because of its ability to increase IGF-1. Interestingly, of the major population studies that made this connection, none found any association between fermented dairy (such as yogurt, kefir, buttermilk, and sour cream) and acne. This aligns with the IGF-1 theory as bacteria ferments IGF-1 in the process of making these products, causing fermented dairy products to have 4x less IGF-1 than skim milk. Additionally, the increased intestinal permeability common in acne patients could increase intestinal absorption of IGF-1, further exacerbating the issue (4).
Furthermore, a high fat diet is suggested to negatively impact skin health by decreasing Bifidobacteria and overall microbial diversity. This then increases intestinal permeability, allowing LPS endotoxins to enter the blood, in turn causing inflammation and insulin resistance (4) (3). On the other hand, fruits and vegetables increase gut microbial diversity, decrease inflammation, and are protective against acne (3).
Overall Message
Overall, the discovery of the gut-skin axis has inspired an abundance of new research into the use of probiotics to cure acne. Certain strains of probiotics may have the potential to significantly improve acne. While probiotics and other supplements and cosmetics are powerful tools, it is important to take a holistic approach to treat acne that considers diet as well as other lifestyle factors such as sleep and stress, as these all impact the health of our skin. Contact us to get started if you are interested in optimizing your gut-skin-axis and treating your acne through your gut!
References
- Chilicka K, Dzieńdziora-Urbińska I, Szyguła R, Asanova B, Nowicka D. Microbiome and probiotics in acne vulgaris—a narrative review. Life (Basel). 2022 Mar 15;12(3):422. https://doi.org/10.3390/life12030422
- Gieler U, Gieler T, Kupfer JP. Acne and quality of life – impact and management. JEADV. 2015 Jun;29(S4):12–4. https://doi.org/10.1111/jdv.13191
- Sánchez-Pellicer P, Navarro-Moratalla L, Núñez-Delegido E, Ruzafa-Costas B, Agüera-Santos J, Navarro-López V. Acne, microbiome, and probiotics: The gut–skin axis. Microorganisms. 2022 Jun 27;10(7):1303. doi:10.3390/microorganisms10071303
- Bowe WP, Logan AC. Acne vulgaris, probiotics and the gut-brain-skin axis – back to the future? Gut Pathog. 2011;3(1):1. https://doi.org/10.1186/1757-4749-3-1
- Goodarzi A, Mozafarpoor S, Bodaghabadi M, Mohamadi M. The potential of probiotics for treating acne vulgaris: A review of literature on acne and microbiota. Dermatol Ther. 2020 Apr 7;33(3). https://doi.org/10.1111/dth.13279
- Lathakumari RH, Vajravelu LK, Satheesan A, Ravi S, Thulukanam J. Antibiotics and the gut microbiome: Understanding the impact on human health. J Med Microbiol. 2024 Jun;20:100106. https://doi.org/10.1016/j.medmic.2024.100106
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